# US 8,771,126 B2 · Traction drive mechanism

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- Number: US 8,771,126 B2
- Document ID: US8771126B2
- Status: Granted
- Kind: B2
- Application number: 13/811,097
- Filed: 2011-06-27
- Published: 2013-05-16
- Granted: 2014-07-08
- Earliest claimed: 2010-07-26
- Assignees: Kabushiki Kaisha Toyota Chuo Kenkyusho
- Applicants: Yoshihiro Mizuno; Kisaburo Hayakawa; Hiroyuki Nishizawa; Hiroyuki Yamaguchi; Kiyokazu Sunami
- Inventors: Yoshihiro Mizuno; Kisaburo Hayakawa; Hiroyuki Nishizawa; Hiroyuki Yamaguchi; Kiyokazu Sunami
- Web page: https://patentgrep.com/patent/US8771126B2

## CPC

- F16H 13/08: with balls or with rollers acting in a similar manner
- F16H 13/06: with members having orbital motion
- F16H 57/0006: {Vibration-damping or noise reducing means specially adapted for gearings (devices for varying tension of belts, ropes or chains with damping means F16H7/0829; toothed members with construction providing vibration damping F16H55/14; reducing vibrations or noise of the gearbox casing F16H57/028; suppression of vibrations or noise of gear selectors F16H59/0208; control of hydrostatic fluid gearing preventing or reducing vibrations or noise F16H61/4183)}
- F16H: GEARING

## Abstract

Assuming that N1 and N2 are the respective numbers of pinion rollers (23, 63); ρ1 is the ratio between the inner diameter of a ring roller (22) and the outer diameter of a sun roller (21); and ρ2 is the ratio between the inner diameter of a ring roller (62) and the outer diameter of a sun roller (61); and it holds that N1=3, and (ρ1+1)×(ρ2+1)≧24+16×20.5, in the case where N2=3, then it holds that ρ1≧0.102×(ρ1+1)×(ρ2+1)+1.196, and ρ1≦min[0.204×(ρ1+1)×(ρ2+1)+3.123, 7+4×30.5], and in the case where N2=4, then it holds that ρ1≧(2−20.5)×(ρ1+1)×(p2+1)/4−1, and ρ1≦min[0.185×(ρ1+1)×(ρ2+1)+1.320, 7+4×30.5].

## Claims

### Claim 1

A traction drive mechanism comprising a first planetary roller mechanism and a second planetary roller mechanism that are connected in series, the first planetary roller mechanism including a plurality of first planetary rollers rotatably supported by a first carrier, the first planetary rollers being held in contact between a first sun roller and a first ring roller, the second planetary roller mechanism including a plurality of second planetary rollers rotatably supported by a second carrier, and the second planetary rollers being held in contact between a second sun roller and a second ring roller, wherein
N1=3, N2=3, 4, 5, or 6, and
(ρ1+1)×(ρ2+1)≧24+16×20.5
in which N1 is the number of the first planetary rollers, N2 is the number of the second planetary rollers, ρ1 is the ratio between the inner diameter of the first ring roller and the outer diameter of the first sun roller, and ρ2 is the ratio between the inner diameter of the second ring roller and the outer diameter of the second sun roller, and
provided that N2=3,
ρ1≧0.102×(ρ1+1)×(ρ2+1)+1.196, and
ρ1≦min[0.204×(ρ1+1)×(ρ2+1)+3.123, 7+4×30.5]
when a value of a smaller one of (0.204×(ρ1+1)×(ρ2+1)+3.123) and (7+4×30.5) is min[0.204×(ρ1+1)×(ρ2+1)+3.123, 7+4×30.5], or
provided that N2=4,
ρ1≧(2−20.5)×(ρ1+1)×(ρ2+1)/4−1, and
ρ1≦min[0.185×(ρ1+1)×(ρ2+1)+1.320, 7+4×30.5]
when a value of a smaller one of (0.185×(ρ1+1)×(ρ2+1)+1.320) and (7+4×30.5) is min[0.185×(ρ1+1)×(ρ2+1)+1.320, 7+4×30.5], or
provided that N2=5,
ρ1≧0.206×(ρ1+1)×(ρ2+1)−1, and
ρ1≦min[0.234×(ρ1+1)×(ρ2+1)−0.480, 7+4×30.5]
when a value of a smaller one of (0.234×(ρ1+1)×(ρ2+1)−0.480) and (7+4×30.5) is min[0.234×(ρ1+1)×(ρ2+1)−0.480, 7+4×30.5], or
provided that N2=6,
ρ1≧0.25×(ρ1+1)×(ρ2+1)−1, and
ρ1≦min[0.278×(ρ1+1)×(ρ2+1)−0.603, 7+4×30.5]
when a value of a smaller one of (0.278×(ρ1+1)×(ρ2+1)−0.603) and (7+4×30.5) is min[0.278×(ρ1+1)×(ρ2+1)−0.603, 7+4×30.5].

### Claim 2 (depends on 1)

The traction drive mechanism according to claim 1, wherein
the second sun roller is coupled to the first carrier, and
the rotations of the first and second ring rollers are constrained.